---
product_id: 621113137
title: "Sea to Summit Reactor Sleeping Bag Liner, Extreme Compact (78 x 31.5)"
brand: "sea to summit"
price: "¥29660"
currency: JPY
in_stock: true
url: https://www.desertcart.jp/products/621113137-sea-to-summit-reactor-sleeping-bag-liner-extreme-compact-78
store_origin: JP
region: Japan
---

# Up to +25°F warmth boost Stretch-knit Thermolite Pro fabric Adjustable drawcord footbox Sea to Summit Reactor Sleeping Bag Liner, Extreme Compact (78 x 31.5)

**Brand:** sea to summit
**Price:** ¥29660
**Availability:** ✅ In Stock

## Summary

> 🔥 Sleep warmer, move freer, camp smarter.

## Quick Answers

- **What is this?** Sea to Summit Reactor Sleeping Bag Liner, Extreme Compact (78 x 31.5) by sea to summit
- **How much does it cost?** ¥29660 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/621113137-sea-to-summit-reactor-sleeping-bag-liner-extreme-compact-78)

## Best For

- sea to summit enthusiasts

## Why This Product

- Trusted sea to summit brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Stretch-Knit Freedom:** Mummy-shaped liner with incredible stretch for unrestricted movement and a perfect fit.
- • **HeiQ Fresh Odor Control:** Stay fresh on multi-day trips with advanced odor-fighting technology built in.
- • **Thermolite Pro Warmth Boost:** Add up to 25°F of cozy heat to your sleep system, perfect for winter adventures.
- • **Drawcord Footbox Ventilation:** Customizable footbox opening lets you regulate temperature or walk around camp comfortably.
- • **Lifetime Sea to Summit Guarantee:** Invest in durability and trust with a lifetime warranty backing your liner.

## Overview

The Sea to Summit Reactor Extreme Sleeping Bag Liner uses advanced Thermolite Pro hollow-core fibers and infrared ceramic pigments to reflect body heat, adding up to 25°F of warmth. Its stretch-knit mummy shape ensures a snug yet flexible fit, while the adjustable drawcord footbox offers ventilation and mobility. Enhanced with HeiQ Fresh odor control, this lightweight 0.81 lb liner elevates your winter camping comfort and hygiene, backed by a lifetime guarantee.

## Description

Sea to Summit Reactor series insulated sleeping bag liners can extend the comfort range and improve personal hygiene of any sleeping bag. Thermolite hollow core fibers are constructed like the fur of a polar bear, efficiently trapping heat and providing a luxuriously soft, comfortable feel. The stretch-knit fabric provides optimal comfort, and ensures the Reactor fits any sleeping bag. Additionally, the drawcord footbox offers plenty of ventilation and the versatility of walking around camp while still wearing your liner. Available in three different weights, Reactor technical liners make your existing sleeping bag warmer and more versatile. The Regular Liner uses hollow-core Thermolite Pro fabric with infra red-absorbing ceramic pigments and Thermolite EcoMade fibers. This lightweight fabric adds up to 14F of warmth to your sleep system. The Extreme Liner features a thicker hollow-core Thermolite Pro fabric to add up to 25F of warmth to your sleep system. The Fleece Liner employs hollow-core Thermolite Pro fibers in a grid-pattern to deliver our warmest sleeping bag liner which adds up to 32F of warmth to your sleep system.

## Features

- Insulated sleeping bag liner adds extra warmth and personal hygiene to any sleeping bag.
- Thermolite Pro technology using knitted, hollow-core fibers and absorbing infrared ceramic pigments to reflect your body's heat back to the wearer for enhanced warmth and comfort
- Drawcord footbox can be opened or closed for optimal comfort and integrates perfectly with the footbox of our Free-Flow Zip system in select Sea to Summit sleeping bags
- HeiQ Fresh odor control technology helps keep the liner fresh even after extended use
- Knitted fabric provides incredible stretch and freedom of movement in this mummy-shaped liner and works seamlessly with sleeping bags of any shape, Sea to Summit Guarantee is offered for the Lifetime of this product

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | Sea to Summit |
| Occupancy | 1 |
| Shape | Mummy |
| Seasons | Winter |
| Temperature Rating | 6 to 15 degrees Celsius |
| Age Range (Description) | Adult |
| Material | thermolite |
| Fill Material | Thermolite |
| Closure Type | Drawstring |
| Item Weight | 0.81 Pounds |
| Outer Material | thermolite |
| Fabric Type | thermolite |
| Global Trade Identification Number | 09327868158317 |
| Manufacturer | Sea to Summit |
| Country of Origin | China |
| Item model number | SS42100 |
| ASIN | B0CT67MSSN |

## Product Details

- **Brand:** Sea to Summit
- **Occupancy:** 1
- **Shape:** Mummy
- **Seasons:** Winter
- **Temperature Rating:** 6 to 15 degrees Celsius

## Images

![Sea to Summit Reactor Sleeping Bag Liner, Extreme Compact (78 x 31.5) - Image 1](https://m.media-amazon.com/images/I/51qJoRiUJpL.jpg)
![Sea to Summit Reactor Sleeping Bag Liner, Extreme Compact (78 x 31.5) - Image 2](https://m.media-amazon.com/images/I/717FGa+RshL.jpg)
![Sea to Summit Reactor Sleeping Bag Liner, Extreme Compact (78 x 31.5) - Image 3](https://m.media-amazon.com/images/I/7142moFOpHL.jpg)
![Sea to Summit Reactor Sleeping Bag Liner, Extreme Compact (78 x 31.5) - Image 4](https://m.media-amazon.com/images/I/81XnJwN4QUL.jpg)
![Sea to Summit Reactor Sleeping Bag Liner, Extreme Compact (78 x 31.5) - Image 5](https://m.media-amazon.com/images/I/818yJJioawL.jpg)

## Available Options

This product comes in different **Style Name** options.

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**Shop now:** [https://www.desertcart.jp/products/621113137-sea-to-summit-reactor-sleeping-bag-liner-extreme-compact-78](https://www.desertcart.jp/products/621113137-sea-to-summit-reactor-sleeping-bag-liner-extreme-compact-78)

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-01-28*